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Extending variable scope from one frame to another frame

I have two JFrame based windows: SeatLayout and BillSummary. I need to get the seatnumber from the SeatLayout frame and display it in BillSummary but the variable scope is limited to the first frame.
How can I do this?

Using multiple JFrame is a bad practice and it should be avoided.
Reason being, it will add more problems in the future and it will be nightmare to maintain.
To answer your question , how to pass variable from your parent(JFrame) to a child(JDialog) .This can achive by using JDialog.
I am going to run through an example.
lets say, your BillSummary.java is ....
//BillSummary Class
public class billSummary {
JFrame frame;
billSummary(JFrame frame) {
this.frame = frame;
}
public void launchbillSummary(int seatNumber) {
// Create a dialog that suits your ui , you can use JPanel as your layout container
JDialog dialog = new JDialog(frame, "Bill Summary", true);
dialog.setLayout(new BorderLayout());
dialog.setSize(100, 100);
dialog.add(new JLabel(Integer.toString(seatNumber)), BorderLayout.CENTER);
dialog.setVisible(true);
}
}
Your seatLayout.java
public class seatLayout {
seatLayout(){
//Lets say you have seleted seat number 10
int defaultSeatNumber = 10;
//Lets say you have a button and when it is clicked , you pass the data to billsummary page
JButton enter = new JButton("Enter");
//Your seatLayout GUI
JFrame frame = new JFrame("seat layout");
frame.setSize(300,300);
frame.add(enter);
enter.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent arg0) {
//Do your passing of data/ price of calculation here
//You pass the data that to your custom dialog -> Bill summary
new billSummary(frame).launchbillSummary(defaultSeatNumber);
}
});
frame.setVisible(true);
}
public static void main(String[] args){
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new seatLayout();
}
});
}
}
I hope this help and answers your question. Good luck :)

Make absolute layout as same size as JFrame at design time for convinience

I am developing a Java Swing application. I have a small issue on how to resize the layout in a JFrame to the same size of the JFrame in the Design tab in Eclipse.
The layout's space is not enough to effectively design my intended user interface. I can add items in a crammed manner and those items display in the final output but at design time I would like the layout to expand as much as the JFrame. Following image would describe my problem:
I tried this code but it does not seem to work:
getContentPane().setPreferredSize(new Dimension(800, 600));
This is my code:
public class ExployeeScreen extends JFrame {
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
ExployeeScreen frame = new ExployeeScreen();
frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
public ExployeeScreen() {
setBounds(100, 100, 450, 300);
setExtendedState(JFrame.MAXIMIZED_BOTH);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
getContentPane().setLayout(null);
getContentPane().setPreferredSize(new Dimension(800, 600));
}
}
Any help regarding this is highly appreciated. Thanks :)

JFrame: All the frames close when I try to close just one of them

public class Scratch {
public static void main(String[] args) {
Dimension d = new Dimension(300,300);
JFrame frame1 = new JFrame("Frame-1");
JFrame frame2 = new JFrame("Frame-2");
frame1.setSize(250,250);
frame2.setSize(d);
frame1.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame2.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame1.setVisible(true);
frame2.setVisible(true);
}
}
When I run this, the two frames show up as expected, but when I close one of them, both of them close. I want to achieve the functionality where only the frame I click 'x' on closes and the other remains open until I click the 'x' on it. How do I do it?

frame1.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame2.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
The "EXIT" tells the JVM to stop so all the windows are closed:
So you could be using:
frame1.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame2.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
Then only the frame you click on will close. When both frames are closed the JVM will exit.
However, that is not a good solution. An application should generally only have a single JFrame and then use a JDialog for a child window. Using this approach the code would be:
JDialog dialog = new JDialog(frame1);
dialog.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
Depending on you requirement you would make the dialog modal or non-modal.
Using this approach the JVM will exit when you close the frame however it will stay open when you close a child dialog.
Read this forum question about multiple JFrames: The Use of Multiple JFrames: Good or Bad Practice?. It will give more thoughts on why using 2 JFrames is not a good idea.

public class Scratch {
public static void main(String[] args) {
Dimension d = new Dimension(300,300);
JFrame frame1 = new JFrame("Frame-1");
JFrame frame2 = new JFrame("Frame-2");
frame1.setSize(250,250);
frame2.setSize(d);
frame1.setVisible(true);
frame2.setVisible(true);
}
}
you add one of them to your frame.
setVisible(false);
dispose();
setDefaultCloseOperation(DISPOSE_ON_CLOSE);

How can I minimize/iconify a JWindow in Java?

My app has a JWindow that needs to be minimized when the custom minimizer button clicked.
Please reply if anyone knows how to minimize a JWindow. I have searched a lot but couldn't find any suitable method to minimize.
I know how to minimize a JFrame. So please don't bother answering regarding JFrame.
Thanks.

I know you don't want to hear this, but the terrible truth is that there is no big difference between undecorated jframes (with setstate methods) and jwindows... :)
JFrame f = new JFrame("Frame");
f.setUndecorated(true);

Due to the fact that a JWindow is not decorated with any control icons, no setState method is provided. One workaround is to allow your custom minimizer button to set the window visible as required:
public class JWindowTest extends JFrame {
JWindow window = new JWindow();
JButton maxMinButton = new JButton("Minimize Window");
public JWindowTest() {
setSize(300, 200);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
maxMinButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (window.isVisible()) {
maxMinButton.setText("Restore Window");
} else {
maxMinButton.setText("Minimize Window");
}
window.setVisible(!window.isVisible());
}
});
add(maxMinButton);
window.setBounds(30, 30, 300, 220);
window.setLocationRelativeTo(this);
window.add(new JLabel("Test JWindow", JLabel.CENTER));
window.setVisible(true);
}
public static void main(String[] args) {
new JWindowTest().setVisible(true);
}
}

One JFrame opening another

I have a JFrame and JPanel full of Jsomethings with an actionlistener. When the user clicks an object I want to open another JFrame. Here is what I did:
public void actionPerformed(ActionEvent e) {
Object source = e.getSource();
if (source == rejectionbutton){
RejectApp ra = new RejectApp();
ra.main(null);
}
}
(RejectApp calls a new JFrame.) So another JFrame opens on the screen with more options. It works OK (so far), but I want to know is this standard? I mean calling the main method like this?
Another question is, without using a cardlayout (which I don't want to use), is the best way to handle multiple panels, by doing this sort of thing?

I would change a few things. First off, usually an application has one JFrame and then if it needs to show another window does so as a modal or non-modal dialog such as can be obtained with a JDialog or JOptionPane. Having said that, it's even more common to have one JFrame and swap "views" in the JFrame -- swap contentPanes or other large panels via a CardLayout as this would mimic the behavior of many gui programs we all currently use.
Personally, I also try to gear my GUI creation towards creating a JPanel or JComponent rather than towards creating a top-level window. This way if I want to display the GUI as a stand alone app, a dialog, or an applet I can pop it into the contentPane of a JFrame or JDialog or JApplet respectively, or if as an inner panel of a more complex GUI, then insert it there, or in an application with a swapping view, then as a card in a CardLayout as noted above. The bottom line is I feel that this structure gives you the developer a lot more options in how you can use this GUI.
Also, I would avoid calling another class's main as you're doing (assuming this is the public static void main method) as you lose all benefits of OOPs. You also seem to be trying to call a static method in a non-static way (assuming I understand your program structure correctly).
For your second question, it begs a question of my own: why do you not want to use CardLayout?
edit: an example of what I meant is as follows:
import java.awt.Dimension;
import java.awt.Window;
import java.awt.Dialog.ModalityType;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
public class SwingEg {
private static void createAndShowUI() {
JFrame frame = new JFrame("Main JFrame");
frame.getContentPane().add(new MainGUI().getMainPanel());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
createAndShowUI();
}
});
}
}
class MainGUI {
private static final Dimension MAIN_PANEL_SIZE = new Dimension(450, 300);
private JPanel mainPanel = new JPanel();
private JDialog modalDialog;
private JDialog nonModalDialog;
public MainGUI() {
JButton openModalDialogBtn = new JButton("Open Modal Dialog Window");
openModalDialogBtn.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
openModalDialogBtnActionPerformed(e);
}
});
JButton openNonModalDialogBtn = new JButton("Open Non-Modal Dialog Window");
openNonModalDialogBtn.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
openNonModalDialogBtnActionPerformed(e);
}
});
mainPanel.setPreferredSize(MAIN_PANEL_SIZE);
mainPanel.add(openModalDialogBtn);
mainPanel.add(openNonModalDialogBtn);
}
private void openModalDialogBtnActionPerformed(ActionEvent e) {
if (modalDialog == null) {
Window topWindow = SwingUtilities.getWindowAncestor(mainPanel);
modalDialog = new JDialog(topWindow, "Modal Dialog", ModalityType.APPLICATION_MODAL);
modalDialog.getContentPane().add(new DialogPanel().getMainPanel());
modalDialog.pack();
modalDialog.setLocationRelativeTo(topWindow);
modalDialog.setVisible(true);
} else {
modalDialog.setVisible(true);
}
}
private void openNonModalDialogBtnActionPerformed(ActionEvent e) {
if (nonModalDialog == null) {
Window topWindow = SwingUtilities.getWindowAncestor(mainPanel);
nonModalDialog = new JDialog(topWindow, "Non-Modal Dialog", ModalityType.MODELESS);
nonModalDialog.getContentPane().add(new DialogPanel().getMainPanel());
nonModalDialog.pack();
nonModalDialog.setLocationRelativeTo(topWindow);
nonModalDialog.setVisible(true);
} else {
nonModalDialog.setVisible(true);
}
}
public JPanel getMainPanel() {
return mainPanel;
}
}
class DialogPanel {
private static final Dimension DIALOG_SIZE = new Dimension(300, 200);
private JPanel dialogPanel = new JPanel();
public DialogPanel() {
dialogPanel.add(new JLabel("Hello from a dialog", SwingConstants.CENTER));
dialogPanel.setPreferredSize(DIALOG_SIZE);
}
public JPanel getMainPanel() {
return dialogPanel;
}
}

I would rather make a new instance of JFrame or a subclass, or call a new method who makes a new JFrame:
public void actionPerformed(ActionEvent e) {
Object source = e.getSource();
if (source == rejectionbutton){
JFrame frame = new JFrame("New Frame");
//or
makeNewFrame();
}
}
Another simple Layout-Manager is the BorderLayout, it´s the default Layout-Manager of the JFrame class.

new YourJFrameNameHere().setVisible(true);
Replace YourJFrameNameHere with the JFrame name.
Simple, no?